Typical display screens occupy a relatively small part of a viewer's, or user's, field of view. A standard computer monitor, television screen, liquid crystal, flat panel, thin-film transistor, or other type of display device might measure 14 to 29 inches diagonal. This requires a user to be relatively close to the display in order for the display to fill up a larger portion of the user's field of view.
Larger displays are possible. For example, a projection display can occupy a much larger area. However, such devices are often expensive and inconvenient. For example, a projector might have to be located at some distance from the screen, or other surface, in order to create a sufficiently large display. Another problem with projection type of displays is that they, in effect, “blow up” a high resolution into a coarser resolution. For example, if a 1024×768 display is projected to create a large image, the image is still at the 1024×768 resolution. The picture elements, or pixels, and spaces between pixels are made larger by projecting. Thus, the pixel density is decreased. This is why projected displays are usually viewed from a larger distance than the display screens mentioned above. A longer viewing distance means that the coarser resolution is not as noticeable.
Another approach is a so-called “wall of video”. This approach uses multiple display screens usually arranged in a rectangle, or wall. Portions of an image to be displayed are divided among the separate display screens in the wall so that a much larger display can be obtained. Note that this approach maintains the display density since each screen is still displaying at its native density. For example, if three screens are used in a row, and each screen has a 1024×768 density, then although three times as much area is covered by the combination of three display screens, there are also three times as many pixels in the composite display.
A problem with the wall of video approach is that it is inflexible and expensive. The system must be designed from the outset so that an image source can appropriately generate separate video signals to each of the screens. Typically, a computer is used to divide a single input image into separate images for the sections of the wall of video. For example, if a wall of video uses 9 screens in a 3×3 arrangement, then the computer system is designed to divide an original image into an equal 3×3 grid. Each section of the grid is sent to the associated display screen. The arrangement is hardwired and is typically designed on a customized, per installation, basis. Setting up such a display requires planning of the area to be covered, size and number of screens to use, multiple display output hardware devices, custom software to divide the input images, etc.
Once a wall of video system is set up it is not easily changed. This makes it difficult to adapt the display to different applications. For example, viewing a movie may require that the screens be arranged in a 4:3 aspect ratio for best viewing. Presenting documents or tables of information might best be achieved if an overall display is taller than it is wide. Playing computer games that simulate immersion into a simulated environment warrant a display area that wraps around a user and that can potentially cover large spherical sections around the user.
Thus, it is desirable to provide a multi-screen display system that improves upon one or more of the shortcomings of the prior art.